1. Technical Field
The inventions relate to noise interference detection and reduction, and in particular, to echo source detection and reduction.
2. Related Art
Microphones may detect and convert received sound into electrical signal. Microphones may detect desired sound, such as speech, music, or other audio. Microphones may also detect interference, such as echoes and speech from other speakers, which may mask or distort the desired sound. The interference may be produced by loudspeakers, reflections off surfaces, or other sources.
Interference may be reduced through a generalized sidelobe canceller. A generalized sidelobe canceller may include process branches that generate a reduced interference signal and a blocking signal that includes interfering components. An interference canceller may subtract portions of the blocking signal from the reduced interference signal to produce an output. However, this technique may attenuate a desired signal. In addition, interference such as echo sounds may be detected as desired signals and distort the output signal. This technique may cause undesirable and unacceptable output signals.